We’ve often come across sums done in the free pages at the back of a manuscript, where some poor monk has taken a date in A.M. (anno mundi) and subtracted 5508 to get the A.D. year.
(But caution: if it’s from the 1st of September to the end of the A.M. year, you have to subtract 5509: in Bodley’s Roe 18(b), for example, the scribe “Constantinus Sapiens” (he calls himself that (fol. 476v): «διὰ χειρὸς ἐμοῦ Κωνσταντίνου τοῦ σοφοῦ»!) dated the manuscript Sept., 6857. A later hand just subtracted 5508 and wrote in the margin «ἔτει τῆς ἐνσάρκου οἰκονομίας ͵ατμθʹ», which in his catalogue the usually careful Henry O. Coxe (vol. 1, sub lem., §62) reproduced without comment, as did Πίνακες. But Paul Moore (who I think never made a mistake in his life) subtracted the right amount and correctly dated this (Iter Psellianum p. 734) to 1348.)
We’ve often wondered though how anyone could actually do sums with Greek numbers, and have joked about “carrying the stigma”. But today, on the otherwise almost blank last folio of a codex, I came across a manuscript where someone does exactly that. I “translated” the numbers and worked it out numeris indo-arabicis and… they got it right!
Interestingly, the dating system they’re using is not the usual one, but that of the antipope Hippolytus, where the earth is eight years younger. (Many thanks to Βλαδιμηρῶπον for telling me about this.) I’ll let the historians comment on the significance of the years themselves.
τ ι η
φ ν ε
ρ κ θ
͵Ϛ ψ ι β
͵Ϛ ψ ξ θ
ρ Ϟ β
͵Ϛ Ϡ ξ α
This translates into the following:
vʹd (año incarnationis domenicæ secũdũ Hippolytũ)
= vʹmdccxii (ca. añum Dom. 1212)
= vʹmdcclxix (ca. añum Dom. 1269)
= vʹcmlxi (ca. añum Dom. 1461)
Or, in the middle ages, perhaps to something like this:
…So, let’s carry that sigma after all!